This invention relates to agronomy, in general, and golf course greens keeping, specifically. One of the most important elements of golf course management is the health of the putting greens. In attempting to maintain the most luxurious growth of grass, close attention is paid to watering and feeding of the greens. However, very little has been done in the area of temperature control, other than watering, even though it is well known that each species of greens grass has an optimum temperature range for best results. This invention provides a system by which the surface temperature of the grass may be changed from the ambient temperature without introducing other deleterious agents.
Temperature control, or cooling, of the golf greens has conventionally been a by-product of watering. However, in the hotter climates or in the hotter parts of the summer, temperature control would require too much water for healthy growth of the grass. Too much water, particularly in high humidity conditions, may create a continuous wet environment more favorable to fungi, mildew, or other deleterious agents. Whereas watering during the heat of the day affects the subsoil which damages the root system of the grass. Therefore, watering, alone, can not be used to control temperature for a sustained period of time.
Large fans, located adjacent the greens, have been employed to control humidity and temperature by moving the air across the green. Any cooling effects are directly related to evaporation and in a high relative humidity environment there is little evaporation. In the situation where there is a low humidity heat, there is no water vapor to evaporate. This amounts to a hot dry wind which dries out the subsoil quicker than normal. In addition to the substantial breeze created by the fans, the noise produced is a distraction to the players.
The art of greens keeping lacks a system which can be used continuously in all high heat and high or low humidity conditions to control the temperature of the air directly above the green without deleterious side effects.
There are numerous devices for affecting the temperature of golf course greens. U.S. Pat. Nos. 5,596,836; 5,617,670; and 5,636,473 to Benson disclose an underground system for delivering treated air to the subsoil of a green. The operation of these devices depend on the specific preparation of the subsoil for their operation. This includes installation of a gravel bed under the green as part of the site preparation. The treated air is delivered underground and percolates upwardly through the gravel bed and the sod to achieve its desired result. U.S. Pat. No. 5,590,980 to Daniel discloses an underground system of conduits connected to a vacuum pump and reservoir to control the moisture content of the green through drainage. Yoshizaki, U.S. Pat. No. 5,306,317 uses an underground conduit system and a boiler for heating the soil for optimum growth. Rearden et al, U.S. Pat. No. 5,368,092, discloses a subsurface array of tubes for circulating a temperature controlling fluid and a temperature sensor for control of the device.
All of these devices attempt to influence the surface temperature of the green from subterranean application of the temperature altering agents. The intervening layers of earth and/or gravel would clearly act as a heat sink and detract from effectiveness of these agents on the upper surface of the grass.
A system for modifying the surface temperature and/or relative humidity of golf greens or other grass playing fields by applying temperature controlled air and/or a water mist through pop-up nozzles. The nozzles are controlled by a central control panel which activates the nozzles based on input from temperature sensitive probes in the greens.
Accordingly, it is an objective of the instant invention to teach the application of temperature controlling agents directly to the upper surface of the grass.
It is a further objective of the instant invention to teach the use of a temperature controlled air flow upon the surface of the grass which may be applied continuously without injury to the grass.
It is yet another objective of the instant invention to teach a system of providing temperature controlled air flow through an array of distribution lines which include the temperature and humidity modification of ambient air and delivery to the upper surface of the green. The system may be controlled by temperature sensitive probes inserted in the sod.
It is a still further objective of the invention to provide a particular nozzle construction for applying the temperature controlled air flow wherein the nozzle is displaced from an at-rest position within the sod to an activated position above the grass. The displacement of the nozzle may be accomplished by air flow.
Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.